The magnetic fields of external galaxies observed with LOFAR
David D. Mulcahy
Jodrell Bank for Astrophysics
Anna Scaife (Jodrell Bank Center for Astrophysics)
There is increasing evidence that magnetic fields can extend deep into the intergalactic space; however as it is far from regions of acceleration, the synchrotron emission is weak due to lack of cosmic rays electrons which suffer from various loss processes.
Fortunately, low energy electrons which emit emission at low frequencies suffer less from energy loss processes and are expected to travel further, especially in the presence of ordered magnetic fields.

This poster will summarise low frequency radio observations of the face-on galaxy, M51, from the LOFAR telescope. In combination with novel theoretical models of cosmic ray propagation, it will address multiple outstanding questions in galactic astrophysics: how far do galactic magnetic disks extend and what is their structure; what is the dominant mechanism of cosmic ray propagation in these regions?